SV flags report
The SV flags report is sent when Command Packet 54h is used to request the status of the SV flags for one satellite or all satellites. The Command Packet 54h SUBTYPE byte (byte 4) is set to twenty (20) when requesting the report.
The following table shows the additional records provided in Report Packet 55h when SV flags data is included:
|
Subtype 20: SV flags report |
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|---|---|---|---|---|
|
Byte |
Item |
Type |
Value |
Meaning |
|
6 |
SAT TYPE |
1 byte |
0–7 |
Specifies the satellite system for the PRN which is being configured: 0: GPS: 1–32 |
|
7 |
MODE |
1 byte |
0–7 |
Mode from the 54h GETSVDATA request: 0: Return SV flags for SAT TYPE |
|
8 |
Number of bytes (n) for each of the following fields. |
1 byte |
1–? |
Number of bytes in each of the following flags. |
|
|
EPHEMERIS FLAGS |
n bytes |
? flag bits |
Flags show availability of ephemeris, LSB = first PRN. Set to 1 when ephemeris is available. |
|
|
ALMANAC FLAGS |
n bytes |
? flag bits |
Flags show availability of almanac, LSB = first PRN. Set to 1 when almanac is available. |
|
|
SV DISABLED FLAGS |
n bytes |
? flag bits |
Flags show disabled SVs, LSB = first PRN. Set to 1 when satellite is disabled. |
|
|
SV UNHEALTHY FLAGS |
n bytes |
? flag bits |
Flags show the health of satellites, LSB = first PRN. Set to 1 when satellite is unhealthy. |
|
|
SV "IGNORE HEALTH" FLAGS |
n bytes |
? flag bits |
Flags show the health of satellites, LSB = first PRN. Set to 1 when satellite is set to ignore health. |
|
---------- End of Subtype 20 ---------- |
||||
The Command Packet 54h subtype 0 message is depreciated and subtype 20 should be used. For reference, the subtype 0 was structured as follows:
|
Subtype 0: SV flags report |
||||
|---|---|---|---|---|
|
Byte |
Item |
Type |
Value |
Meaning |
|
6–9 |
EPHEMERIS FLAGS |
4 (double word) |
32 flag bits |
For all satellites, the flags show availability of ephemeris data when set to 1 where bit #0 corresponds to PRN 1. |
|
10–13 |
ALMANAC FLAGS |
4 (double word) |
32 flag bits |
For all satellites, the flags show availability of almanac data when set to 1. |
|
14–17 |
SV DISABLED FLAGS |
4 (double word) |
32 flag bits |
Flags show Enabled or Disabled status of all satellites. Set to 1 when satellite is disabled. |
|
18–21 |
SV UNHEALTHY FLAGS |
4 (double word) |
32 flag bits |
Flags show the health of satellites. Set to 1 when satellite is unhealthy. |
|
22–25 |
TRACKING L1 FLAGS |
4 (double word) |
32 flag bits |
Flags show satellites tracked on L1 when set to 1. |
|
26–29 |
TRACKING L2 FLAGS |
4 (double word) |
32 flag bits |
Flags show satellites tracked on L2 when set to 1. |
|
30–33 |
Y-CODE FLAGS |
4 (double word) |
32 flag bits |
Flags show satellites with Anti-Spoofing turned on when set to 1. |
|
34–37 |
P-CODE ON L1 FLAGS |
4 (double word) |
32 flag bits |
Flags show satellites which are tracking P-code on L1. Flags are not set for satellites not tracked on L1. |
|
38–41 |
RESERVED |
4 (double word) |
32 flag bits |
Reserved (set to 0). |
|
42–45 |
RESERVED |
4 (double word) |
32 flag bits |
Reserved (set to 0). |
|
46–49 |
RESERVED |
4 (double word) |
32 flag bits |
Reserved (set to 0). |
|
50–53 |
RESERVED |
4 (double word) |
32 flag bits |
Reserved (set to 0). |
|
---------- End of Subtype 0 ---------- |
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